Comparative circulating tumor DNA levels for KRAS mutations in patients with nonresectable pancreatic cancer.

288 Background: Non-resectable pancreatic cancer patients have a wide range of median time for overall survival (OS). Currently there is a lack of diagnostic tools to predict patient outcome at diagnosis. KRAS mutations are present in the vast majority of pancreatic tumors. The study objective was to determine if quantitative baseline and longitudinal monitoring of KRAS mutations from plasma circulating tumor DNA (ctDNA) could be used to stratify patients for predicting outcome. Methods: Plasma was prospectively collected from the Danish BIOPAC study for non-resectable pancreatic cancer patients undergoing treatment with gemcitabine or FOLFIRINOX. Feasibility of monitoring ctDNA KRAS mutations was assessed in 10 patients with long OS (median 493 days; range 360-1031) and 10 patients with short OS (median 66 days; range 21-136). KRAS G12A/C/D/R/S/V, and G13D mutations were PCR enriched, sequenced by massively parallel deep sequencing, quantitated and standardized by reporting number of copies detected per ...